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TCI : Target Controlled Infusion
Basic knowledge & Clinical experience
on
นพ.วิโรจน เพง ผล โรงพยาบาลราชบุรี
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TIVA : Why ? What ?1
Basic principle of TIVA & TCI2
TCI : Pharmacokinetics & Model 3
Induction, maintenance & emergence4
TCI : Advantage & clinical application5
TCI: Precaution & pitfalls6
LOGODisadvantage of InhalationsDisadvantage of Inhalations
1
Global warming
Work place pollution
3
•Nausea-vomiting •Emergence dysphoria•↑ICP, ↑IOP•Inhibit autoregulation
& HPV(hypoxic pul vasoconstriction)
•Trigger MH
2
Specific equipment anesthetic machine + vaporizer
Special ventilatory technique &compromised airway seals : bronchoscopy,
Environment Environment TechniqueTechnique InhalationsInhalations
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TTIVAIVA ::Total Intravenous anesthesia
the use of IV agentsexclusively to provide
a complete anesthetic condition
ImmobilityAnalgesia
opioids –
Morphine, fentanyl, remifentanil
dexmedetomidine, ketamine, NSAID
propofol, thiopentone,
midazolam dexmedetomidine,
non-depolarize muscle relaxant
Balancedanesthesia
DefinitionDefinition
Hypnosis
LOGODevelopment of delivery systems
Single injection, Intermittent injection,
Continuous iv. drip
Infusion pumpSyringe pump
Control rate
1st 2nd
AIMAIM maintenance of optimum & stable anesthetic condition
stable
plasmaconcentration
Bolus + elimination
Elimination
LOGODevelopment of delivery systemsDevelopment of delivery systems
22ndnd Infusion pumpSyringe pump : control rate
Controllable infusion rate
Intermediate blood supply
: muscle
Poor bl.supply
:fat
Rich blood supply
LOGOTIVATIVA--MCI: manually controlled infusionMCI: manually controlled infusion
LessPain
With N2
OWithout
N2
O
Start 8 10 12>10 mins. 5 7 9
>2 hrs. 3 5 7
Initial infusion rate 10 minSubsequence adjustmentso as to maintain a stable level of anesthesia
Not easy to control Not easy to control TimeTime--consuming calculationconsuming calculation
No compensate for interrupted infusionNo compensate for interrupted infusion
Delayed emergence !!!Delayed emergence !!!Require skill & experienceRequire skill & experience
““are used to designate
manual adjustment of infusion rates for anesthesia syringe pumps”
duration stop1 ชม. 10
นาที
3 ชม. 15 นาที4 ชม. 20 นาที
mg/kg/hr
LOGODevelopment of delivery systemsDevelopment of delivery systems
Single injection, intermittent injection,
Continuous iv. drip
Infusion pumpSyringe pump
TIVA:MCI
Target controlled Infusion
TIVA: TCI
1st 2nd 3rd
AIMAIM maintenance of optimum & stable anesthetic condition
LOGOTarget controlled infusion : TCITarget controlled infusion : TCIis an infusion system which allows the anaesthetist to
select the target blood concentrationrequired for a particular effect,
and then to control depth of anaesthesia by adjusting the requested target concentration
LOGOOpen, threeOpen, three--compartment modelcompartment model
Cet : effect targetSchneider model
Cp : plasmaMarsh model
Variable rate
LOGOTCI: basic principleTCI: basic principle
infusion rates are altered automatically according to a validated pharmacokinetic model
(Propofol :Marsh, Schnider, Remifentanil : Minto model)
Anesthesiologist selects
and inputs targets
blood concentration
TCI SubsystemMicroprocessor
+pharmacokinetic program
Patient
Infusion pump incorporating
1.Age 2.BW3.Height 4.Sex
LOGOTCI: pharmacokinetic modelTCI: pharmacokinetic model
Model
Drug specific : Remifentanil : Minto modelPropofol : Schneider model
A drug : different PKPropofol : Marsh model
Schneider model
LOGOB.E.T.schemeB.E.T.scheme
Targetconcentration
TransferCompensate for peripheral distribution
Decreasing infusion rate= Ct x V1
(k12
e(-k21
t)+k13
e(-k31
t))
Bolus
Fill central compartment
Bolus dose = Ct x V1
EliminationCompensate for
metabolism & elimination
= Ct x CL=Ct x K10
x V1
AIMAIMTo achieve a chosen concentration
LOGODrug for TCI : hypnoticsDrug for TCI : hypnotics
2 hrs.infusion→100 mins
3 hrs.infusion →25 mins
LOGODrug for TCI : analgesicsDrug for TCI : analgesics
Ideal for TCI
LOGOOpen loopTCI: propofol Open loopTCI: propofol
Fresofol in Syringe 50 ml Extension , 3-way
Syringe TCISchneider modelKey patient data
selectTarget Cet
1st 2nd 3rd
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Target = ?
CP50 2.7–3.4 µg/ml loss of response to verbal or tactile stimuli*
Cet 2-3 µg/ml loss of eyelash reflexCet 4-8 µg/ml for
anesthetic procedureIntubation, LMA
* : Vuyk J et al.
Anesthesiology 1992;
77:
3.
Crankshaw DP et al.
Anaesth Intensive Care 1994;
22:
481.
Smith C et al.
Anesthesiology 1994;
81:
820.
TCITCI--propofol concentrationpropofol concentration
Target concn based on•Level of stimulation•Drug interaction•Desired clinical endpoint•Individual variability
LOGOTCI for induction & intubationTCI for induction & intubation
Premedication : MO 5-10 mg, midazolam 1-2 mgInduction : propofol Cet 2-3 µg/ml
Check for loss of consciousness : eyelash reflex
Check for ventilation if OK muscle relaxationIntubation : Non-depolarize muscle relaxant 90-180 sec
Propofol Cet 4-8 µg/ml 45-60 sec
After taping endotracheal tube : no stimuli ↓Cet 2-3 µg/ml next painful stimuli : before skin incision ↑Cet 4-6 µg/ml
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titratetitrateUse TCI syringe as a iv. vaporizer for Fresofol Titrate depth of anesthesia to optimum level
bybyseverity of stimuli : more severe↑Cet, less severe:↓Cet clinical signs : HR, BP, movement, sweating, pupil sizedepth monitor: BIS, CSI
tricktrick ↑Propofol Cet before noxious stimuli↓Propofol Cet after a period of infusionTo achieve hemodynamic stability
rememberrememberAdequate analgesics & muscle relaxant supplementBlood & Volume replacementCheck for signs of awareness
TCI for maintenanceTCI for maintenance
LOGOPrepare for emergencePrepare for emergence
• Propofol Cet maintenance 3-5 µg/ml → 4 µg/ml • Set wake up concn 1.5-2.0 µg/ml → 2 µg/ml
• wake up time = time from 4→2 µg/ml = X min• X min to end of operation→ Stop or Cet 0.01 µg/ml• Observe Propofol Cet & clinical, BIS
• Usually wake up < 1.5-2.0 µg/ml →later than wake up time• Reverse MR → extubation
Rescue dose for unexpected event !!
LOGOCheck TCI advantage : post op.Check TCI advantage : post op.
non-idealenvironment
Not inhibit HPV
↓IOP
Clear headedrecovery ↓ICP ↓CMR
↓emesis
Do not prescribe prophylaxis for
PONVDate of BirthOrientation
Emergence delirium
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LOGOTCI advantages & clinical applicationTCI advantages & clinical application
non-idealenvironment
Not inhibit HPV
↓IOP
Clear headed recovery without delirium ↓ICP ↓
CBF↓CMR
↓emesis
Laporoscopic Sx.ObstetricsGI surgeryEye, ENT
Hx of PONVneurosurgery
Day case surgeryNeuro exam
X-rays ER
MilitaryDeveloping
country
Open eye injury
One lung ventilation
LOGOTCI for neuroanesthesiaTCI for neuroanesthesia
Goal : : Not only an adequate anesthetic condition (amnesia/sedation, analgesia, immobility & hemodynamic stability)
..BUT..
1. optimal operating conditions 2. neurological protection3. rapid emergence from anesthesia for
neurological examination
LOGOGoal I : optimal neurosurgical conditionGoal I : optimal neurosurgical condition
↓ICP
Low CBFAdequate
CPP
minimal brain bulk
↓
CMR O2
Optimal operating condition
LOGOspecific effects of IV. & inhalationsspecific effects of IV. & inhalations
Drug CBF CMR
ketamine Increase increase
nitrous oxide increase increase
halothane increase decrease
enflurane increase decrease
isoflurane increase decrease
desflurane increase decrease
sevoflurane increase decrease
thiopental decrease decrease
etomidate decrease decrease
propofol decrease decrease
LOGOTCI for neuroanesthesiaTCI for neuroanesthesia“Volatile anesthetics have been shown to affect
…cerebral autoregulation and intracranial pressure…which can make the surgery more difficult and dangerous, increasing the risk of …….ischemic cerebral insults”
“ the reduction in cerebral blood flow with ↑
in cerebral vascular resistance and ↓
CMRO2
seems to make TIVA ..the more advantages anesthesia technique ..
for patients with increased ICP ”
: :Todd MM et al: Anesthesiology 78:1005-1020,1993
: Neurosurgery 61[ONS suppl 2] : ONS369-ONS378,2007
LOGOGoal II : cerebral protection Goal II : cerebral protection
Pharmacologic technique
Non - pharmacologic
technique
↓O2 demand↑O2 supply
Avoid ischemia
LOGONonNon--pharmacologic techniquepharmacologic technique
Good venous returnUpright head
HemodilutionHct 30-34 %
euvolemia
Mild hypothermia1۫c ↓CMRO2
7% 32-35 ۫ ۫c protection
not recommendAvoid hyperthermia
Glusoce control< 150 mg/dl> 60 mg/dl
Avoid Hypoxia, Hypercarbia
PaCO2
28-32 mmHg
Avoid hypotensionMAP > 70 mmHgSAP > 90 mmHg
CPP = MAP-ICP = 60-70
Brain protection
LOGOPharmacologic techniquePharmacologic technique
↓Ca
++,↓Na+
influx
↓free radical
IV. Agent
•Thiopental•Propofol
•Local anesthetics
But not Ketamine
Inhalation
•Isoflurane•Sevorane
•Desflurane
But not halothane,
N2 O
Prevent apotosis
Block ischemic cascade
↑GABA,↓NMDA
LOGOGoal III : rapid emergence for neuroexam. Goal III : rapid emergence for neuroexam.
Isoflurane
Propofol
Sevoflurane
Desflurane
slow fast faster fastest
Clear headness dysphoria ?
LOGORatchaburiRatchaburi’’s experiences experience
Induction : TCI Propofol Cet 2-3 → 6-8 µg/ml → 2-3 µg/ml
Air:O2, Fentanyl, Midazolam, Muscle relaxants
Maintenance : TCI Propofol →Cet 4-6 µg/ml
(Cet 6.2 µg/ml burst suppression)
End point :
systemic hypotension is a major contributor to poor outcome –
avoid
SBP < 90 mmHg level II*
BP BIS
* www.braintrauma.org
ICP
40 -
50brain relaxation & surgical access
LOGOMost common pitfallsMost common pitfalls
Delayed awakening Movement Hypotension Not deep
enough
Unfamiliar
BIS,CSI
delayedmuscle relaxant
Supplement
Neuromuscular monitoring
Hypovolemia
Fluid statusevaluation
Unsecured iv. access
Always checked !!
LOGOOther problemsOther problems
Awareness Bradycardia agitationBIS diff.
from clinical
Unfamiliarlong dead space
Inadequateanalgesics
BIS,CSI
On ß-block ? judgement
LOGOprecaution
Not recommend for TCI-propofolNot recommend for TCINot recommend for TCI--propofolpropofol
No available model placental transfer Drug metabolite
Age <15 BW>150BW>150 C/SLiver
impairment
LOGOPropofolPropofol--related infusion syndromerelated infusion syndrome
High dose infusion >5 mg/kg/hr for > 48 hrs
Abrupt onset of profound bradycardia, metabolic acidosis , lipemic plasma,
renal failure, fatty liver, rhabdomyolysis or myoglobinuria
Risk factors
: poor oxygen delivery, sepsisserious cerebral injury
Monitor
: acidosis, K+, renal function
symptomssymptomssymptoms
LOGOTake home message :Take home message :
TCI
Simple…. to operateContinuous process…
from induction through to maintenance
Easy to titrate…
the level of anesthesiaGood control of depth…
of anesthesia
Improved control …of cardiovascular and respiratory parameters
Try it !!
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